Power consumption is of particular concern in limited-power devices (e.g., battery-powered devices) such as laptops and notebooks, smart phones, touchscreen devices, gaming consoles, and the like. These devices are limited in size and weight and generally portable, and therefore they typically use smaller and lighter batteries of limited capacity.
With dynamic frequency scaling, the clock rate for the device's central processing unit (CPU) can be reduced to decrease power consumption during periods of relative inactivity. For example, the device may be used to browse the Internet and scroll through a Web page, in which case the device is active and the CPU is operating at its “normal” clock rate. However, when the user stops scrolling (e.g., while reading the Web page), the device is relatively inactive and its power requirements are consequently less; thus, the device's power consumption can be decreased to save power by decreasing the CPU's clock rate. When the user again starts scrolling or browsing again, the CPU's clock rate needs to be increased (boosted) to accommodate the increased level of activity.